MeOSuc-AAPV-pNA, Chromogenic Substrate is a sensitive chromogenic substrate for PR3 (proteinase 3; PRTN3) and neutrophil elastase. PR3 is a polymorphonuclear leukocyte (PMNL) serine proteinase that degrades a variety of matrix proteins including fibronectin, laminin, vitronectin, and collagen type IV and contributes to the proteolytic generation of antimicrobial peptides. Neutrophil elastase is a serine proteinase that during inflammation, is secreted by neutrophils to destroy bacteria as well as host tissue. Evaluating human and murine PR3 and neutrophil elastase enzymes are helpful to understanding PR3-related and inflammatory autoimmune processes. Researchers have used this product in cystic fibrosis research, as elastin degradation has been reported to increase in cystic fibrosis patients. Hydrolysis or cleavage of this substrate product can be detected at 405-410 nm. This product is not a suitable substrate for cathepsin G nor chymotrypsin.